<!DOCTYPE html>
<html lang="en">
<head>
    <style>
        .well {
            margin-bottom: 10px;
        }
    </style>
    <title>下拉框页面</title>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css">
    <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
    <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script>
    <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
</head>
<body>

<div class="container">
    <h2>下拉菜单</h2>
    <div class="well">
        <div class="dropdown">
            <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
                Dropdown button1
            </button>
            <div class="dropdown-menu">
                <a class="dropdown-item" href="#">Event1</a>
                <a class="dropdown-item" href="#">Event2</a>
                <a class="dropdown-item" href="#">Event3</a>
            </div>
        </div>
    </div>

    <div class="well">
        <div class="dropdown">
            <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
                Dropdown button2
            </button>
            <div class="dropdown-menu">
                <a class="dropdown-item" href="#">Event1</a>
                <a class="dropdown-item" href="#">Event2</a>
                <a class="dropdown-item" href="#">Event3</a>
            </div>
        </div>
    </div>

    <div class="well">
        <div class="dropdown">
            <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
                Dropdown button3
            </button>
            <div class="dropdown-menu" id="super1">
                <a class="dropdown-item" href="#">Event1</a>
                <a class="dropdown-item" href="#">Event2</a>
                <a class="dropdown-item" href="#">Event3</a>
            </div>
        </div>
    </div>
    <div class="well">
        <div class="dropdown">
            <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
                Dropdown button4
            </button>
            <div class="dropdown-menu">
                <a class="dropdown-item" href="#">Event1</a>
                <a class="dropdown-item" href="#">Event2</a>
                <a class="dropdown-item" href="#">Event3</a>
            </div>
        </div>
    </div>

</div>

</body>
</html>
